Histological sections stained with safranin-O for the CaP group. This area is the posterior of the aperture site in the femur. T = tendon graft, B = bone, C = cartilage tissue, UF = uncalcified fibrocartilage-like tissue, CF = calcified fibrocartilage-like tissue. (a) Low-magnification image (x 12.5). The cartilage layer with glycosaminoglycan stained red was observed between the tendon graft and the bone. (b) Magnified views of boxed part in (a) (x 100). The interface shows 4 distinct layers, namely, tendon graft, uncalcified fibrocartilage, calcified fibrocartilage layer, and bone tunnel. (c) Magnified views of the boxed part in (b) (x 400). The cartilage layer shows 2 distinct layers, namely, uncalcified fibrocartilage and calcified fibrocartilage layer without tidemarks.